While guitarists, by necessity, have a loose approach to finding the right notes for a chord, and will often use an inversion to get them all (or at least the harmonically important ones, like the third) on the fretboard in a reasonable way, that doesn't change the meaning of fourth and fifth. It's a bit pedantic, sure, and the notes have the same harmonic meaning (sort of, though inversions do feel different sometimes), but when you lay out the standard tuning of a guitar out on a piano and ask someone the distance, it is a fourth. You have to jump through some hoops to convince them to tell you that the relationship between the G to the D below it is a "perfect fifth".
I'll also point out that the post I was responding to had already established which way he was counting by describing the relationship between the G and B strings (which, if we're counting the other direction would be a flat 6th; and, as a musician of twenty years I had to do mental somersaults to make my brain think of it that way). One way or another the description of standard guitar tuning was incorrect.
See what you made me do? I had to go all pedantic and stuff, and I hate doing that.
No, it depends on the distance between the notes, which in the standard guitar tuning is a fourth (except between G3 and B4, as mentioned). You can take the lower note an octave up or the higher an octave down to make a fifth, but that changes the interval.
I'll also point out that the post I was responding to had already established which way he was counting by describing the relationship between the G and B strings (which, if we're counting the other direction would be a flat 6th; and, as a musician of twenty years I had to do mental somersaults to make my brain think of it that way). One way or another the description of standard guitar tuning was incorrect.
See what you made me do? I had to go all pedantic and stuff, and I hate doing that.